Aroma diffuser



FIG. 1 is a front view of an ornamental design for an aroma diffuser showing our new design;

FIG. 2 is a rear view of an ornamental design for the aroma diffuser;

FIG. 3 is a left side view of an ornamental design for the aroma diffuser;

FIG. 4 is a right side view of an ornamental design for the aroma diffuser;

FIG. 5 is a plan view of an ornamental design for the aroma diffuser;

FIG. 6 is a bottom view of an ornamental design for the aroma diffuser; and,

FIG. 7 is a perspective view of an ornamental design for the aroma diffuser.

The broken lines in the drawings illustrate portions of the aroma diffuser which form no part of the claimed design. 

CLAIM The ornamental design for an aroma diffuser, as shown and described. 